entry
    let sum :=
        [1, 2, 3, 4, 5]
            . { Seq }
            . { map &(x) => (10 * x) }
            . { filter &(x) => (x != 50) }
            . { reduce (0, &(sum,x) => (sum + x)) },
    { sys::println { String sum } }
        . { crash-on-error };
